NRAOCASA: casa::ROArrayMeasColumn< M > Class Template Reference

Before a column can be accessed it must have previously been defined as a Measure column by use of the TableMeasDesc object.

    // Read/write MEpoch array column
    MEpoch::ArrayColumn ec(table, "ColumnName);
    // Readonly MDoppler array column
    MDoppler::ROArrayColumn dc(table, "DopplerCol");

Reading and writing Measures

The reading and writing of Measures columns is very similar to reading and writing of "ordinary" Table columns. get() and operator() exist for reading Measures and the put() member for adding Measures to a column. (put() is obviously not defined for ROScalarMeasColumn objects.) Each of these members accepts a row number as an argument.

Care needs to be taken when adding Measures to a column. The user needs to be aware that Measures are not checked for consistency, with respect to a Measure's reference, between the Measures being added to a column and the column's predefined Measure reference. This is only an issue if the Measure column was defined to have a fixed reference. For such columns the reference component of Measures added to a column is silently ignored, that is, there is no warning nor is there any sort of conversion to the column's reference should the reference of the added Measure be different from the column's reference. The members isRefVariable() and getMeasRef() can be used to discover a Measure column's Measure reference characteristics.

Example

       // create an MEpoch array column object
       MEpochArrCol arrayCol;
   
       // should be null.  Can test this and attach a real MEpoch column
       // The column Time1Arr should exist in the table and would have been
       // defined by using a TableMeasDesc
       if (arrayCol.isNull()) {
            arrayCol.attach(tab, "Time1Arr");
       }
   
       // This would throw an Exception if the object is still null.\..\.but
       // hopefully won't
       arrayCol.throwIfNull();
   
       // create a vector of MEpochs
       MEpoch last(Quantity(13.45, "h"), MEpoch::Ref(MEpoch::TAI));
       Vector<MEpoch> ev(10);
       for (uInt i=0; i<10; i++) {
           last.set(Quantity(13.45 + i, "h"));
           ev(i) = last;
       }
   
       // before adding something check the isDefined() member
       if (!arrayCol.isDefined(0)) {
           cout << "PASS - nothing in the measure array column row yet\n";
       } else {
           cout << "FAIL - there shouldn't be a valid value in the row!\n";
       }
   
       // add the MEpoch vector to the array Measure column at row 0
       arrayCol.put(0, ev);
   
       // now read the array from the row.  Could use same object to do this
       // but here we'll create a ROMEpochArrCol to do this
       ROMEpochArrCol roArrCol(tab, "Time1Arr");
   
       // need a vector to put the MEpochs into
       Vector<MEpoch> ew;
   
       // setting the resize parameter to True automatically sets ew to the
       // same shape as the array contained in the row
       arrayCol.get(0, ew, True);

Motivation

The standard Aips++ Table system does not support array Measure columns. This class overcomes this limitation.

Thrown Exceptions

Constructor & Destructor Documentation

template<class M>

casa::ROArrayMeasColumn< M >::ROArrayMeasColumn ( )

The default constructor creates a null object.

Useful for creating arrays of ROArrayMeasColumn objects. Attempting to use a null object will produce a segmentation fault so care needs to be taken to initialise the objects by using the attach() member before any attempt is made to use the object. A ROArrayMeasColumn object can be tested if it is null by using the isNull() member.

template<class M>

casa::ROArrayMeasColumn< M >::ROArrayMeasColumn	(	const Table &	tab,
		const String &	columnName
	)

Create the ROArrayMeasColumn from the table and column Name.

Member Function Documentation

template<class M>

void casa::ROArrayMeasColumn< M >::attach	(	const Table &	tab,
		const String &	columnName
	)

Attach a column to the object.

Reimplemented from casa::ROTableMeasColumn.

template<class M>

void casa::ROArrayMeasColumn< M >::get	(	uInt	rownr,
		Array< M > &	meas,
		Bool	resize = `False`
	)			const

Get the Measure array in the specified row.

For get() the supplied array's shape should match the shape in the row unless resize is True.

template<class M>

Array<M> casa::ROArrayMeasColumn< M >::convert	(	uInt	rownr,
		const M &	meas
	)			const `[inline]`

Get the Measure array contained in the specified row and convert it to the reference and offset found in the given measure.

Definition at line 210 of file ArrayMeasColumn.h.

Referenced by casa::ROArrayMeasColumn< casa::MFrequency >::convert().

template<class M>

Array<M> casa::ROArrayMeasColumn< M >::convert	(	uInt	rownr,
		const MeasRef< M > &	measRef
	)			const

Get the Measure array contained in the specified row and convert it to the given reference.

template<class M>

const MeasRef<M>& casa::ROArrayMeasColumn< M >::getMeasRef ( ) const [inline]

Get the column's reference.

Definition at line 223 of file ArrayMeasColumn.h.

template<class M>

ROArrayMeasColumn& casa::ROArrayMeasColumn< M >::operator= ( const ROArrayMeasColumn< M > & that ) [private]

Assignment makes no sense in a read only class.

Declaring this operator private makes it unusable.

template<class M>

void casa::ROArrayMeasColumn< M >::cleanUp ( ) [private]

Deletes allocated memory etc.

Called by ~tor and any member which needs to reallocate data.

template<class M>

Array<M> casa::ROArrayMeasColumn< M >::doConvert	(	uInt	rownr,
		typename M::Convert &	conv
	)			const `[private]`

Get the data and convert using conversion engine.

Member Data Documentation

template<class M>

ROArrayColumn<Double>* casa::ROArrayMeasColumn< M >::itsDataCol [private]

Definition at line 232 of file ArrayMeasColumn.h.

template<class M>

ROScalarColumn<Int>* casa::ROArrayMeasColumn< M >::itsRefIntCol [private]

Definition at line 234 of file ArrayMeasColumn.h.

template<class M>

ROScalarMeasColumn<M>* casa::ROArrayMeasColumn< M >::itsOffsetCol [private]

Definition at line 241 of file ArrayMeasColumn.h.


Public Member Functions
	ROArrayMeasColumn ()
	The default constructor creates a null object.
	ROArrayMeasColumn (const Table &tab, const String &columnName)
	Create the ROArrayMeasColumn from the table and column Name.
	ROArrayMeasColumn (const ROArrayMeasColumn< M > &that)
	Copy constructor (copy semantics).
virtual	~ROArrayMeasColumn ()
void	reference (const ROArrayMeasColumn< M > &that)
	Change the reference to another column.
void	attach (const Table &tab, const String &columnName)
	Attach a column to the object.
Array< M >	convert (uInt rownr, const M &meas) const
	Get the Measure array contained in the specified row and convert it to the reference and offset found in the given measure.

void	get (uInt rownr, Array< M > &meas, Bool resize=False) const
	Get the Measure array in the specified row.
Array< M >	operator() (uInt rownr) const

Array< M >	convert (uInt rownr, const MeasRef< M > &measRef) const
	Get the Measure array contained in the specified row and convert it to the given reference.
Array< M >	convert (uInt rownr, uInt refCode) const

const MeasRef< M > &	getMeasRef () const
	Get the column's reference.
Protected Attributes
MeasRef< M >	itsMeasRef
Private Member Functions
ROArrayMeasColumn &	operator= (const ROArrayMeasColumn< M > &that)
	Assignment makes no sense in a read only class.
void	cleanUp ()
	Deletes allocated memory etc.
Array< M >	doConvert (uInt rownr, typename M::Convert &conv) const
	Get the data and convert using conversion engine.
Private Attributes
ROArrayColumn< Double > *	itsDataCol
ROScalarColumn< Int > *	itsRefIntCol
ROArrayColumn< Int > *	itsArrRefIntCol
ROScalarColumn< String > *	itsRefStrCol
ROArrayColumn< String > *	itsArrRefStrCol
ROScalarMeasColumn< M > *	itsOffsetCol
ROArrayMeasColumn< M > *	itsArrOffsetCol

casa::ROArrayMeasColumn< M > Class Template Reference
[TableMeasures]

Detailed Description

template<class M>
class casa::ROArrayMeasColumn< M >

Intended use:

Review Status

Prerequisite

Synopsis

Reading and writing Measures

Example

Motivation

Thrown Exceptions

Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

casa::ROArrayMeasColumn< M > Class Template Reference [TableMeasures]

Detailed Description

template<class M> class casa::ROArrayMeasColumn< M >

Intended use:

Review Status

Prerequisite

Synopsis

Reading and writing Measures

Example

Motivation

Thrown Exceptions

Public Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

casa::ROArrayMeasColumn< M > Class Template Reference
[TableMeasures]

template<class M>
class casa::ROArrayMeasColumn< M >